Rapid highly sensitive general protein quantification through on-chip chemiluminescence

Protein detection and quantification is a routinely performed procedure in research laboratories, predominantly executed either by spectroscopy-based measurements, such as NanoDrop, or by colorimetric assays. The detection limits of such assays, however, are limited to μM concentrations. To establish an approach that achieves general protein detection at an enhanced sensitivity and without necessitating the requirement for signal amplification steps or a multicomponent detection system, here, we established a chemiluminescence-based protein detection assay. Our assay specifically targeted primary amines in proteins, which permitted characterization of any protein sample and, moreover, its latent nature eliminated the requirement for washing steps providing a simple route to implementation. Additionally, the use of a chemiluminescence-based readout ensured that the assay could be operated in an excitation source-free manner, which did not only permit an enhanced sensitivity due to a reduced background signal but also allowed for the use of a very simple optical setup comprising only an objective and a detection element. Using this assay, we demonstrated quantitative protein detection over a concentration range of five orders of magnitude and down to a high sensitivity of 10pgmL−1, corresponding to pM concentrations. The capability of the platform presented here to achieve a high detection sensitivity without the requirement for a multistep operation or a multicomponent optical system sets the basis for a simple yet universal and sensitive protein detection strategy.     

Socioeconomic status impacts genetic influences on the longitudinal dynamic relationship between temperament and general cognitive ability in childhood: The Louisville Twin Study

The current analysis investigates genetic and environmental influences on the bidirectional relationships between temperament and general cognitive ability (GCA). Measures of GCA and three temperament factors (persistence, approach, and reactivity) were collected from 486 children ages 4–9 years (80% white, 50% female) from the Louisville Twin Study from 1976 to 1998. The results indicated a bidirectional dynamic model of temperament influencing subsequent GCA and GCA influencing subsequent temperament. The dynamic relationship between temperament and GCA arose primarily from shared genetic variance, particularly in families with higher socioeconomic status, where input from temperament contributed on average 20% to genetic variance in GCA versus 0% in lower SES families.     

The control of upper body segment speed and velocity during the golf swing

Understanding the dynamics of upper body motion during the downswing is an important step in determining the control strategies required for a successful and repeatable golf swing. The purpose of this study was to examine the relationship between head, thorax, and pelvis motion, during the downswing of professional golfers. Three-dimensional data were collected for 14 male professional golfers (age 27 +/- 8 years, golf-playing experience 13.3 +/- 8 years) using an optical motion analysis system. The amplitude and timing of peak speed and peak velocities were calculated for the head, thorax, and pelvis during the downswing. Cross-correlation analysis was used to examine the strength of coupling and phasing between and within segments. The results indicated the thorax segment had the highest peak speeds and peak velocities for the upper body during the downswing. A strong coupling relationship was evident between the thorax and pelvis (average R2 = 0.92 across all directions), while the head and thorax showed a much more variable relationship (average R2 = 0.76 across all directions). The strong coupling between the thorax and pelvis is possibly a method for simplifying the motor control strategy used during the downswing, and a way of ensuring consistent motor patterns.     

Repeatability of three-dimensional thorax and pelvis kinematics in the golf swing measured using a field-based motion capture system

Field-based methods of evaluating three-dimensional (3D) swing kinematics offer coaches and researchers the opportunity to assess golfers in context-specific environments. The purpose of this study was to establish the inter-trial, between-tester, between-location, and between-day repeatability of thorax and pelvis kinematics during the downswing using an electromagnetic motion capture system. Two experienced testers measured swing kinematics in 20 golfers (handicap < or =14 strokes) on consecutive days in an indoor and outdoor location. Participants performed five swings with each of two clubs (five-iron and driver) at each test condition. Repeatability of 3D kinematic data was evaluated by computing the coefficient of multiple determination (CMD) and the systematic error (SE). With the exception of pelvis forward bend for between-day and between-tester conditions, CMDs exceeded 0.854 for all variables, indicating high levels of overall waveform repeatability across conditions. When repeatability was compared across conditions using MANOVA, the lowest CMDs and highest SEs were found for the between-tester and between-day conditions. The highest CMDs were for the inter-trial and between-location conditions. The absence of significant differences in CMDs between these two conditions supports this method of analysing pelvis and thorax kinematics in different environmental settings without unduly affecting repeatability.     

Factorial validity of the Reynolds Intellectual Assessment Scales for referred students

The Reynolds Intellectual Assessment Scales (RIAS) is a recently developed, individually administered psychometric instrument designed to measure general cognitive ability, as well as verbal (crystallized) intelligence, nonverbal (fluid) intelligence, and memory. Test reviewers have recommended the use of the RIAS despite the fact that, although the RIAS has been in circulation for more than four years, there is a paucity of independent research published about its psychometric properties. The purpose of the current study was to examine the factor structure of the RIAS across three samples of school‐age children: the RIAS norming sample; the data reported by Nelson, Canivez, Lindstrom, and Hatt; and a new, independent sample of students referred for special education services. Using confirmatory factor analytic techniques, this study found that a two‐factor model, positing verbal and nonverbal factors, fit all three data sets better than a one‐factor model. Furthermore, the two‐factor model demonstrated partial measurement invariance across the three samples, although the verbal factor showed much stronger invariance, construct reliability, and overall interpretability than did the nonverbal factor. Implications of this study for practitioners are discussed. © 2009 Wiley Periodicals, Inc.     

Social identity theories and educational engagement

There is a large body of research in studies of schooling, particularly ethnographic case studies, which posits that collective action among students undermines engagement in school and contributes to educational inequality. In this paper I review studies of engagement from a social identity theory perspective. To what extent can collective action explain why some student groups are less engaged than others? I discuss four approaches to identifying social identity‐related problems of engagement frequently used in prior research. While researchers often find problems of engagement among low‐academic‐status students, research on educational engagement has had difficulty locating the underlying causes of inequality in student engagement. Social identity theories of educational engagement are inherently theories of collective action. I conclude that a fifth approach, large‐scale observational studies of monitoring and sanctioning, provides the best framework for identifying both the prevalence of, and solutions to, this particular source of disengagement.     

Social network analysis: a simple but powerful tool for identifying teacher leaders

Instructional teacher leadership is central to a vision of distributed leadership. However, identifying instructional teacher leaders can be a daunting task, particularly for administrators who find themselves either newly appointed or faced with high staff turnover. This article describes the use of social network analysis (SNA), a simple but powerful tool that can help administrators better understand the connectedness of their network and pinpoint influential individuals within it. We offer practical guidance for conducting SNA, generating and modifying a sociogram, and interpreting the resultant data. Additionally, we suggest that information provided by SNA may be used to inform decisions about school/district programmes and policies.     

The effect of foil on paddling efficiency in a short surfboard

Surfboard volume and shape affect human performance while riding waves, but little is known regarding the impact of these variables on paddling, where surfers spend a majority of their time. The purpose of this study was to determine whether changing the foil (fore/aft thickness profile) of a short surfboard will alter paddling mechanics and efficiency if surfers are allowed to self-select their prone position. Twenty recreational surfers paddled three different surfboards in a freshwater swim flume while measurements of drag force, board motion, body position, heart rate, and oxygen use were acquired. All boards shared the same volume (31 L) and gross dimensions (172.7 cm long × 50.8 cm wide × 6 cm thick), but the geometric center was placed in a different location along the fore/aft axis of each board. Surfers were blinded to the volume and shape of each board. Results indicated that surfers positioned their center of mass further forward in response to a more nose-heavy board and further aft in response to a more tail-heavy board (22.04 ± 6.34 mm difference in position between boards, p = 0.008). This self-selected positioning yielded no statistical difference in drag force, board angle and accelerations, heart rate, or oxygen use across the three boards. These data suggest that when surfboard volume and gross dimensions are fixed, foil has little effect on the efficiency of paddling a short surfboard in recreational athletes.